1. Field of the Invention
The present invention relates to enzymatic liquid detergent compositions comprising lipolytic enzymes and a nonionic polymeric stabilizing agent for the lipolytic enzymes.
2. Description of the Related Art
Enzymatic liquid detergent compositions are well-known in the art. Most of the prior proposals are however concerned with enzymatic liquid detergent compositions which contain a proteolytic enzyme ingredient, or a mixture thereof with amylolytic enzymes.
One of the problems, inherent to the use of enzymes in liquid detergent compositions is their stability in such liquid detergent compositions. The art is crowded with a variety of proposals to improve the stability of enzymes, particularly proteolytic and/or amylolytic enzymes in liquid detergent compositions.
In U.S. Pat. No. 4,715,990 (Crossin), enzymatic liquid detergent compositions are described which comprise a proteolytic and/or an amylolytic enzyme and a salt of a lower carboxylic acid such as sodium format as stabilizer for these enzymes. The compositions furthermore comprise a soil-release promoting polymer which is a water-soluble or water-dispersible polymer of polyethylene terephthalate or polyoxyethylene terephthalate.
Lipolytic enzymes have also been proposed for inclusion in liquid detergent compositions, although to a much lesser extent than proteases and/or amylases.
In U.S. Pat. No. 3,950,277 (Stewart et al), lipolytic enzymes are described in a pre-soaking composition for fabrics, whereby the pre-soaking composition also contains a lipase activator which can be a polyoxyethylene derivative of ethylenediamine.
In U.S. Pat. No. 3,944,470 (Diehl et al.) and U.S. Pat. No. 4,011,169 (Diehl et al.) certain aminated polysaccharides are proposed as enzyme-stabilizing agent, i.e. for lipolytic enzymes.
In U.S. Pat. No. 4,272,396 (Fukano et al.), enzymatic detergent compositions which may comprise lipase are described, which compositions also contain certain polyethyleneglycols as foam control agents.
In U.S. Pat. No. 4,711,739 (Kandathil), water-in-oil emulsion-type prespotter laundry compositions are described which may contain lipolytic enzymes and certain water-insoluble polyester or polyether polyols as enzyme stabilization agents. These compositions also contain a substantial amount of hydrocarbon solvents.
It is an object of the present invention to stabilise lipolytic enzymes with particular nonionic polymers in liquid detergent compositions. It is another object of the present invention to stabilize mixtures of lipolytic and proteolytic enzymes with particular nonionic polymers in liquid detergent compositions. A final objective of this invention are isotropic liquid detergent compositions containing a stable lipase, alone or in combination with protease, and containing the particular nonionic polymers dissolved therein without the aid of hydrocarbon solvents.